Oscillators are used in a variety of electronic circuits. For example, analog circuitry may use an oscillator for functions such as timekeeping, sampling, etc. As another example, digital circuitry may use an oscillator as a source of clock signals. As another example, mixed-signal or mixed-mode circuitry may use one or more oscillators to generate timekeeping signals, sampling signals, clock signals, and the like.
A real life, practical implementation of an oscillator deviates from an ideal model. For example, output signals of practical oscillators may vary in frequency and/or amplitude based on a number of electrical or environment factors. The electrical factors include supply voltage variations, load variations, etc. The environmental factors include temperature changes, shock, etc.
The description in this section and any corresponding figure(s) are included as background information materials. The materials in this section should not be considered as an admission that such materials constitute prior art to the present patent application.